Art of extracting gum.



PATENTED 00T. 13, 1903i lim-741,256,

W. A. LAWRENCE. ART OP EXTRAGTING GUM. A'PPLIOATION FILED JULY 2, 1902.

N0 MODEL.

iro plants by a continuous process.

' j of india-rubber and is very its physical and chemicalcharacteristics,

l Copalin,n Jiguhite,

iateted oetoter 13, 196:3.

W'ILLIAM A. LAWRENCE, OF

RUBBER COMPANY, OF NEW JERSEY.

SPECIFIAIN forming part of Letters Patent No.

V Application filed July 2, 1902. Serial No. 114,082.

To all whom it muy concern: -y

Be it known that LWVILLIAM ALAWRENCE,

-a citizen oi' the United States, residing' in the borough of Queens,city and( State of New 5 York, have invented certain new and usefulImprovements in the Art of Extracting Gum, of which the atollo Wing is aspecification.A y My invention has lfor its obj-ect the extraction ofrubber or rubberlike Vgums from Y This process VI willr proceed todescribe in detail, reference being mode to the accompanying drawing asshowing one form or" apparatus'rwhich maybe y used to carry out myinvention.

The scope of the invention will be defined in the appended claims. y Itis well known that a certain plant or' shrub which is known to botanistsas Pew6- i henum argento/fum contains a. considerable quantity of rubberor rubber-like gum, which maybe extracted therefrom and which pos-`sesses many or all of the valuable properties similar thereto in Thisplant or shrub grows in large quantities in' Mexico, where it iscommonly known by the names of Guayule, I-lule, wiile,

and Yerba del Negro. v l l While my invention is particularly adapted tothe extractonof gum from therplant above mentioned, l do not desire tolimit myself to the use of this plant, but to use any and all- Aplantsfrom which a rubber or rubber-like guur 'or utta-perchnJ may beextracted' by the process or processes claimed? The first step in mycontinuous process' is the treatment oit' he plant with a solvent forthe rubber or rubberlike gurn contained Before doing this, however,prefer to macerate the plant in some manner in' order that the solventmay extract 'the gum "therefrom in the moet thorough manner and r yThisnley be ac#- 45 'complished in several ways-aa for exanb ple,byrunning the plants betWeeruoorrngated` roughenedrollers, and therebycrushing iny the least possible time.

thestalks, brar 'hs-s, and twigs, or by sliepv pingthe'plantsinto smallpieces. :The niac- NEW YORK, Y., AssIGNoR To CONTINENTAL JERSEY CITY,NEW JERSEY, A `CORPORATION ory Autor EXTRAs-nwo GUM.v

741,256, dates ocmbei` 13, 19,03.

(No sneimens.

eratedA .plants are then treatedwith a solvent,

as4 above mentioned. The solvent which I prefer to use on `account of.its eheapness and the eiectix'enesswith which ity penetrates the barkand wood and dissolves the'gu'ms therein is naphth'a. Other volatilesolvents may,

however, be used, suchv as other hydrocarbonl solvents of rubber,(gasolene, benzin,l benether, chloroform, carbon bisuld, and carbontetrachlorid. Any one .of these solvents may be used and is covered bythe term suitable solvent in the claims, It has heretofore been proposedto treat rubber-bearing' plants in this manneri and then obtain arubber-like product by evaporating from the solution all or nearly allof the naphtha. This process has two serious disadvantages, however.

In the .irst place I have found thatwhen one attempts to drive off thenaphtha'by heat, While the greater portion evaporates .very readily apoint is soon reached, especially Where the lower or heavier grades ofnaphtha are'used, when evaporation takes place very slowly. Itis verydesirable to use as low a grade .of naphtha as possible on account ofthe cheapness of the low grades, and in practice I have found. that theuse in Inyprocess of naphtha of about 74 good results. Such naphthay asthis', however, contains some oil which is above'/l" and is more easilyevaporated than the bulk of the oil, and also much oil which is below 74and very much less rapidlyev'aporated. Infact, l have foundthat the lastor residual portion of the naphtha, being held by the heavy mass ofrubber,requires for its evaporationa very long application of heat. Forexample,1 have Baume gives very.

subjected asolut'ion of the kind described to a yernperatu're of 270Fahrenheit, (which is heldto be the maximum that can be used-Withoutdanger of injuring the rubber) with the result that seventydve per cent.of the naphtha was evaporated in sixty-one mincontinuous ,t

'utes, while further treatment of the residue .for seven hours resultedin a product stillcontaining about thirteen per cent. of its weight Suchaprooess as, this, thereF of naphtha;

yfore,'results'e-ith'ver in an inferior product cow taining naphtha orelse requires the expenditure of a great amount of heat and labor toentirely eradicate the naphtha.

The second disadvantage of the naphtha process heretofore used is thatthe product obtained is not a pure rubber, but contains a largepercentage of resin, inasmuch as the l naphtha dissolves both the rubberand the the consistency of cream.

resin contained in the plants. The product is therefore greatly inferiorto that obtained by my method. v

In the process invented by me I proceed with the evaporation of thenaphtha until I reach a point where further evaporation becomes somewhatdifficult, although there is still a considerable percentage of naphthaor other solvent remaining. At this point I introduce into the rubbersolution a hot alkaline solution, as a solution of sodium hydrate orcaustic soda, or, preferably, the rubber solution is introduced into thealkaline solution, the temperature of which may be nea-ritsboiling-point. The alkali is a very good solveut for the resins andrapidly dissolves them. Tl1e` efect of this is to separate the gum fromthe residue of the naphthaor other solvent. This separation is due tothe fact that the said solvent is volatile and is for the most partevaporated by the hot alkaline solution. The dissolving by the alkali ofthe resins breaks up the gummy mass and permits the volatilization ofthe naphtha or other solvent. Furthermore, the alkaline solution to someeX- tent dissolves the solvent. The result is that the gum rises to thesurface in a mass of about By treating` this rubber product with coldwater all of the "alkali iswashed out and the gum hard ens into a doughymass and may then be rolled into sheets. ner is remarkably free fromimpurities, is highly elastic, and possesses many or all of Vthevaluable properties of the high grades of ordinary india-rubber.

It has also` been proposed to obtain rubber or rubber-like gums fromplants by treating the plants directly with an alkaline solution; Invthis process the woody fibers and bark are attacked by the alkali, andthe rubber being therebyliberated rises to the'top and may be lskimmedoff. This method is greatly inferior to mine, however, in that smallpieces of twigs, wood, woody fiber, &c. are unavoid-` ably mixed withthe rubber and cannot readily be eradicated. In my method the gums arefirst dissolved, and it is evident that the solution may be' strained,so' as to contain no foreign particles Whatever. Furthermore, enoughalkali in the old process must be used to completely disintegrate theplants; otherwisc much ofthe gum'will be retained in the plant. Thisrequires several times as much alkali as is needed in my process, wherethe alkali performs an entirely different f inction, being -used merelyto dissolve the resins from the residuum remaining after evaporation,thereby breaking up the gummy mass and The product obtained in this ma-Ain position.

-evaporating and dissolvingthe residucof the extracting solvent. l

Myprocess is a very economical one, in that the greater part of thenaphtha used may be recovered for further use and only a small quantityof alkali is necessary. 1 A new and useful composition of matter isformed as a by-product inthe carrying out of my process' and forms thesubject-matterof a divisional application, tiled October G, 1902,

Serial No. 126,087.

I will now describe one form of apparatus which may be used in carryingout my invern tion.

The drawing shows the apparatus in vertical section, the same beingarranged in such a manner that gravity aids largely in handling thematerials and solutions.

The rubber4bearing plants are first macer- I ated or crushed in anysuitable manner, pref' erabl y on a floor above the parts shown. Theyare then dropped through an opening in the fioor into the cage or basketThis cage is constructed with steel ribs and is lined with wire-clothhaving a fine mesh. The cage rests upon trunnions 4, which are supportedby the track 5. The cage having been filled with the plants is nowpushed forward and tilted, so as to enter the extracting-drum 6.

upon which the trunnions 4 of the cage rest. The drum 6 is surrounded bya steam-jacket 8, which is supplied from the steam-pipe 16, the dripbeing carried olf by the pipe 17.

9 is a pressure-gage, and 10 isa thermome- Vter extending into theinterior of the drum 6.

After the cage has been run into the drum the 'same' is tightly closedby the door 11, which bears against a gasket 12 and is bolted The valve13 is now opened and naphtha is pumped intofthe tank by the depressedpump 14 through the pipe 15. I I have obtained good results by the useof naphtha of from 62 to 80 Baume in the proportion of about twentyparts by weight to one part of the macerated plant.. By naphtha IA meanthe product ordinarily derived from petroleum and allied to gasolene andbenzin, which are equivalent thereto. The valve 13 having then beenclosed, steam is admitted to the steam-jacket until the pressure-gageofA the drum 6 registers sixty pounds, the thermometer indicating at thesame time from 110 to 114 Fahrenheit. The extractor is kept at thispressure for four hours, which appears to be a suflicient treatment tothoroughly dissolve the gums and resins contained in the plants, thoughthis may vary with different kinds of plants treated and the extentl towhich they have been macerated. At this point I draw off the solutionthrough the pipe 18, which empties into the evaporator 19 through thestrainer 20. Any suitable formof evaporator may be used, the one shownbeing a still surrounded by a steamjacket 2l, having inlet and outletpipes 22 v and 23. The evaporated solven'tis condensed This drum isprovided with two tracks 7, as shown,

IIO

VIO

venete `in the Worin 24 and lovrs into vthe supply-tank naphtha may bereadily driven oft by the ap.-

plication of heat, and no diiiicnlty is encountered until the thickeningot' the solution begins to render evaporation inorc dillicnlt. When sucha point as this is reached and the solution in 4,the evaporatorcontains, say,

. thirty per cent. of naphtha to seventy per cent.

iis

of other inatter, I 'open the discharge-valve 28, and the hot solutionpasses into the tank 29, containing a hot alkaline solution. This rnaybe an open steam jaclieted tank, as shown, in order to keep the alkalinesolution hotand to permit the grim to be readily removed therefrom, orthe tank 29 may be a closed tank in order that that portion oi' theresidue of the solvent used in extracting` the gn'm vand resins whichare evaporated by the hot alkaline' solution may be recovered. in thiscase the part of the tank 29 above the alkaline solution should beprovided. with a pipe leading to a suitable refrigerator, The alkalinesolution is admitted through the pip-e 30. l'have' secured desirableresults ny the use of a tWelve-per-cent. solution of sodium hydrate,(although a weaker solution may be nsecL) introducing therein one-fourthits volume of the naphtha, gum, and resin solution. The yliquidin thetank is then keptat boilingpoint withl occasional stirring for about twohonrs At the end oli 'this time the alkali and heat4 have entirelyseparated the resin and naphtha from the rubber-like gum, and as thesolution'cools or is cooled the latter floats. in a mass of about theconsistency ol cream Cooling may be hastenedby the introduction of cold'waterfrorn the pipe 3l. The ,gum :is now drawn or skimmed off andsubjected to repeated Washings of iii-st hot and then cold water in thetank 32. Under this treatment the goin assumes greater consistency,similar to that of doughV lt may then be readily handled and rnn throughrolls into sheets. The rubber thus Aobtained is of reinar able purityand .of excellent quality for nee in manufacture.

l have also discovered that hot alcohol 'ina-y' be used as asubstitntefor or equivalent of the alkaline solution in the Yprocess just de-vscribed.

This process is exactly siinilar to that described, the only differencebeing that the gum as it separates, being heavier than alcohol, settlesat the bottoni of the taal:

v may be removed after the liquids have been 4naphtha is gotten rid ofby evapora-tion.

drawn off, Whereas the solution of sodium. hydrate previously describedis a feeble solvent of naphtha andthe bulkof the residual Aloohol is avery good solvent of naphtha, and While a portion of thev residualnaphtha is evaporated by the heated alcohol the bulk of it: is dissolvedby thelalcohol.

I have shown and described an apparatus suitable for carrying ont nl yprocess by the of entr:P

,of the saine is left in the residue.

'considerable amount of naphtha remains en tangled oy the inaoeratedplants and also in the form oi' vapor. This naphtha may be recovered bythe use of an apparatus disclosed in United States Letters Patent No.450,501, according to the method therein set forth.V i l have not vshownsuch apparatus in this appli; cation in order to avoid confusion, buthave shown the steam-pipe b communicating' with the interior of the drumG folta-dinitting the steam, the exit-pipe` hand the pipe 3l for intro-lucing the naphtha recovered by the ap paratus into thesnpplyhtanli: 25.

It is not at all necessary that the i a justreferred to should be nso-:lin i ting' gnni, though obvious more economical to do so.

' in this description for the salie of brevity lhave used prominentlythe terni naphtha as a solvent of rubber, but l'do not .confine myselfto that solvent, but include also any of the hydrocarbon solvents ofrobber and such 'Well-known solventsascther, chloroform, carbonbisuliid, carbon tetrachlorid, or any niixf tures of these solvents,and` though i may have nsed only the term rubber ,l include alsogntta-percha in my application as sul ject to the sainczprocess, withonly such riations as will be readilyinanifest to any one versed in thes.

Iain aware that thas been proposed to treat plants containing milkyjuice, snc i as caont chene, with n. solvent, and then to r orpractically all ci the solvent bydi'silla to then treat the residue ofeaout zcpwith alkaline solution, as set i r the British Ilja-mnt Np.11,56? of i885 lconsider my invention to be radicallyv Froni thisprocess, however, as by in, inver:` tion only a portion or" the solventis removed. by distillation and a considerable percentage This remainingsolvent is removed by means of the alkaline or alcoholic solution. avoidcarrying on the distillation'after it .becornes difcnlt and avoid alldanger 'of injnring' the gum. j

Having now fully disclosed any invention, what 1 claim, and desire tosecure by Letters atenn'is- 1.. The art of extracting'rnbber orrobberlilie guin from plants, which consists in treating 'the plantsWith a suitable solvent for the grim, and then treating the solution,While it contains a considerable percentage of solvent,

with an alkaline solution, whereby the gum is separated, venbstantiallyas described.

pnaratns d I thereby 2; The artof extracting rubber or rnbhergum isseparated, substantially as described.

3. The' art of extracting rubber or rubberlike gums from plants,Wliiclrconsists in treating the plants with a suitable solvent for thegum, and then treating the solution, while it contains a considerablepercentage of solvent, with a solution of sodium hydrate, whereby thegum is separated, substantially de- No. 'fitti/15:6.

4. The art of extracting' rubber or rubberlike gunisfroni plants, whichconsists in treating` the plants with a hydrocarbon solvent for the gum,and then treating; the solution, while it contains a considerablepercentage of solvent, with ay solution of sodium hydrate, whereby thegum is separated,substantially ,as described.-

5. The art of extracting rubber or rubberlike gu m from plants, whichconsists in treating theV plants with a suitable solvent for the gumsand resins of the plants, evaporating; a portion of the solvent, andtreating the residue While it contains a considerable percentage of thesolvent, with a heated reagent which is a solvent of the resins of theplants and is anon-solvent of theguin, substantially as described.

6. The art of extracting rubber or rubbervcase in the Patent Office.

[s EAL .j

requiring correction, .as follows: On page 3, line 58, a period shouldbe substituted i like gum from plants, which consists in treating theplants with a hydrocarbon solvent 35 for the gums and resinsol theplants, evaporating a portion of the solvent, and treating the residuewhile it contains a considerable percentage of the solvent, With aheated reagent which is a solvent of the resins of the 4o -k plants andis a non-solvent of thegum, substantially as described.

'7. The art of extracting rubber or rubberlike gum from plants, whichconsists in treatin?,` the plants with a suitable solvent for the 4 5gum, evaporating a portion of the solvent until a residue remains whichstill contains a considerable percentage of the solvent, and thendissolving out the remainder of the sol.- vent from the said residue, bymeans of a 5o heated reagent which is a non-solvent of the gun,substantially as described.

8. The art of extracting rubber or rubberlike gum-frein plants, whichconsists in treating the plants with' a hydrocarbon solvent 55 for thegum, evaporating a portion of the solvent until a residue remains whichstill contains a considerable percentage of the solvent, and thendissolving ou't the remainder of the solvent 'from the said residue bymeans of a 6o heated reagent which is a non-solvent of the gum,substantially as described.-

VVlLlZl'AM A. L ALVRENCE. Witnesses: JAMES' J. Cosuuoin',

DELos HOLDEN i It is hereby certified that in Letters Patent No.741,256, granted October 13, 1903,

upon the application of William A. Lawrence, of New York, N. Y., for animprovement in the Art of Extracting Grunn7` errors appear yin theprinted specication for the comma after the Word olf, and the Followingword.whereas should commence'with a capital W; in line 61, same page, acomma should be substituted for the period after the Word eyaporation,and the following word Alcohol7 should comv nience with asmall o'.instead of a capital; and thatthe said -Letters Patentl should be readwith these corrections therein that the same may conform to the recordof the y* Signed and sealed this 27th day of October, A. D., 1908.

F.` I. ALLEN, Commissioner of Patents.

gum is separated, substantially as described.

3. The' art of extracting rubber or rubberlike gums from plants,Wliiclrconsists in treating the plants with a suitable solvent for thegum, and then treating the solution, while it contains a considerablepercentage of solvent, with a solution of sodium hydrate, whereby thegum is separated, substantially de- No. 'fitti/15:6.

4. The art of extracting' rubber or rubberlike gunisfroni plants, whichconsists in treating` the plants with a hydrocarbon solvent for the gum,and then treating; the solution, while it contains a considerablepercentage of solvent, with ay solution of sodium hydrate, whereby thegum is separated,substantially ,as described.-

5. The art of extracting rubber or rubberlike gu m from plants, whichconsists in treating theV plants with a suitable solvent for the gumsand resins of the plants, evaporating; a portion of the solvent, andtreating the residue While it contains a considerable percentage of thesolvent, with a heated reagent which is a solvent of the resins of theplants and is anon-solvent of theguin, substantially as described.

6. The art of extracting rubber or rubbervcase in the Patent Office.

[s EAL .j

requiring correction, .as follows: On page 3, line 58, a period shouldbe substituted i like gum from plants, which consists in treating theplants with a hydrocarbon solvent 35 for the gums and resinsol theplants, evaporating a portion of the solvent, and treating the residuewhile it contains a considerable percentage of the solvent, With aheated reagent which is a solvent of the resins of the 4o -k plants andis a non-solvent of thegum, substantially as described.

'7. The art of extracting rubber or rubberlike gum from plants, whichconsists in treatin?,` the plants with a suitable solvent for the 4 5gum, evaporating a portion of the solvent until a residue remains whichstill contains a considerable percentage of the solvent, and thendissolving out the remainder of the sol.- vent from the said residue, bymeans of a 5o heated reagent which is a non-solvent of the gun,substantially as described.

8. The art of extracting rubber or rubberlike gum-frein plants, whichconsists in treating the plants with' a hydrocarbon solvent 55 for thegum, evaporating a portion of the solvent until a residue remains whichstill contains a considerable percentage of the solvent, and thendissolving ou't the remainder of the solvent 'from the said residue bymeans of a 6o heated reagent which is a non-solvent of the gum,substantially as described.-

VVlLlZl'AM A. L ALVRENCE. Witnesses: JAMES' J. Cosuuoin',

DELos HOLDEN i It is hereby certified that in Letters Patent No.741,256, granted October 13, 1903,

upon the application of William A. Lawrence, of New York, N. Y., for animprovement in the Art of Extracting Grunn7` errors appear yin theprinted specication for the comma after the Word olf, and the Followingword.whereas should commence'with a capital W; in line 61, same page, acomma should be substituted for the period after the Word eyaporation,and the following word Alcohol7 should comv nience with asmall o'.instead of a capital; and thatthe said -Letters Patentl should be readwith these corrections therein that the same may conform to the recordof the y* Signed and sealed this 27th day of October, A. D., 1908.

F.` I. ALLEN, Commissioner of Patents.

t is herehy certified that in Letters Patent-No. 741,256, grantedOctober 13, 1903, upon the application of William A. Lawrence, of N ewYork, N. Y., for mi improvement in the "Art of Extracting Gumff errorsappear in the printed specification requiring correction, as follows: Onpage 3,1ine 5S, a period should be substituted for the comma after theiivord om and the following word whereas should commeneewith a capitalW; in line 6l, same page, :L comma should be substituted for the periodafter the word evaporation, and the following word Alcohol shouldconimence with' a, small a instead of a. capital; and that the saidLetters Patent should be read with these corrections therein that thesame may conform to the record of the case in the Patent Oilice.v

I Signed and sealed this 27th day of October, A. D., 1903.

F. I. ALLEN,

[SEAL] Commissioner of Patents.

